Feed leg for rock drills



June 16, 1964 M. WORMAN FEED LEG FOR ROCK DRILLS 2 Sheets-Sheet 1 Filed Oct. 27, 1960 in I! .i T

INVENTOR MART/N WORMA/V \mmkk HIS ATTORNEY |8A IOA lOB United States Patent O 3,137,313 FEED LEG FOR ROCK DRILLS Martin Worman, Phillipsburg, N.J., assignor to Ingersoll- Rand Company, New York, N.Y., a corporation of New Jersey Filed Oct. 27, 1960, Ser. No. 65,342 Claims. (Cl. 137-596) This invention relates to control valves and more specifically to valves of the type for controlling a feed leg for power tools such as rock drills.

Up to this time feed legs for rock drills have been single acting (power extensible, manually retractable) and a single valve element has been used to control the amount of air going to the leg. This valve merely controls the quantity as no directional control was required. With the advent of double acting feed legs (power extensible and power retractable) a directional control valve is now required incorporating a quantity flow control when extending the leg and must have means for immediate disconnect of the air pressure from .both sides of the fluid motor (feed leg) for emergency conditions.

An object of this invention is to provide a directional control valve for a double acting feed leg'for rock drills.

Another object ofthis invention is to provide a valve for rock drills and the like to control a double acting feed member beinglpositive acting and of such character as to be capable of withstanding the high shock forces imparted thereto.

These and other objects of this invention will become apparent by referring to the following description and the accompanying drawing in which FIGURE 1 is an elevational view of a rock drill and a feed leg therefor including a control valve device in accordance with the subject invention,

FIG. 2 is a sectional view taken on line 22 of FIG. 1,

FIGS. 3, 4 and 5 are sectional views taken on line.33 of FIG. 2, illustrating the valve in three operative positions,

FIG. 6 is a sectional view taken on line 6-6 of FIG. 2, and

the backhead of the drill 10 and is locked therein by a nut 28. The leg portion 30 has three spaced annular grooves 32, 34 and 36 forming chambers within the bore 11, the chambers communicating with the passages 18A, 10A and 10B, respectively. The intervening lands between the annular grooves form seals thus segregating each of the formed chambers from one another. The bracket 24 has a valve bore 40 threaded at one end as at 42,and,.an Y I end wall 44 with an opening 46 therethrough being smaller in size than the bore itself.

The chamber formed by. the annular groove 36 is connected to the transverse bore 26 by an internal passage 48 while the chamber formed by the annular groove 34 communicates with a passage 50; the passage 50 being connected to the valve bore 40 by a passage 54. The chamber'forme'd by the annular groove 32 communicates with an internal passage 52; the passage '52 being connected to-thevalve bore 40 by passage 58. The transverse .bore 26in the bracket 24 is further connected to the valve bore 40 by two passages 60 and 62 while a port 64 connectsthe bore 26 to atmosphere. For simplicity, the passage 62, as'shown, connects with the passage 48 instead of directly connecting to the bore 26.,

The grip 22 is comprised of three major parts, a fixed tubular gripping portion 70, a rotational gripping portion 72 outward of the fixed portion 70 and an internal rotary valve 74 operatively connected to the portion 72-. The tubular portion 70 has a'reduced end 68 sweated into or otherwise retained in the transverse bore 26 of the bracket 24 and'is held rigid therein. The reduced portion 68 has a plurality of drilled holes which communicate with the various passages that intersect the bore 26 and for descriptive purposes will be considered as an integral part of the specific passage with which they, communicate. I

' The rotary valve 74'has a chamber '76 and three ports 78, 80, and 82 axially spaced from one another and adapted'to communicate with the passages 48, 60 and 64,

FIG. 7 is a sectional view taken on line 77 of FIG. 2, i

Referring now to FIG. 1, a rock drill 10 is conventionally shown having a bracket 12 for receiving a double acting feed leg 14. The feed leg 14 has motor chambers 14A and 14B, and, a ground engaging portion 16 at the 1 free end thereof. The drill feed line 18 is the only external conduit associated with the drill as the'remaining air passages are incorporated within the structure. The drill 10 has ahandle 20 attached thereto which houses a flow control valve 74 and a directional control valve 90 as will be described. I

The drill 10 has a tapered transverse bore 11 at the bottom of the backhead of the drill body which ,is intersected by three air passages 10A, 10B and 18A as may be seen in FIG. 2. The air passages 10B and 10A connect the bore 11 to the top and bottom motor chambers 14A and 14B, respectively, of the feed leg 14. The passage 18A is an extension of the air supply line 18 and connects the control valve device for the drill to the bore 11.

The handle 20 is formed of a grip 22 mounted in a transverse bore 26 in a handle bracket 24 and forms, in part, the flow control valve housing 70. The bracket 24 has a leg portion 30 received in the tapered bore 11 in v bore 40 to urge the valve 90 2 Wall 44; Thespring 110 normally holds the valve 90 in respectively. The inner wallof the member or the 1 outer wall of the valve 74 has an annular groove 84 in communication with the passage. 4 8-and the port 78in such a manner that the chamber 76 is in constant communication with thepassage 48 regardless of the angular position of the valve 74. The ports 80 and 82 are angularly disposed relative one to the other and are adapted to communicate with/the passage 60 and the port 64, respectively. The valve 74 has a metering groove 86 which extends about one quarter of the periphery of the valve from the port 80 and reduces insize toward its end remote-from the portas may be seen in FIG. 7. A second metering groove 88 similar to the groove 86extends from the port 82 in a reverse direction. The grooves 86 and 88 are metering grooves for the rotary valve 74 as will be further explained.

A sl ide valve 90 is received inthe bore 40 and has a reduced plunger portion 92 extending through the opening- 46 inthe end wall 44 of the bracket arm 24. The valve 90 has a blind bore 94-to receive a spring 110. There is an alternate series of lands and grooves 100, 102, 104, 106-, and 108,:respectively, which ,form the outer surface ofthe valve 90. Spring 110 is held in place by a plugIlZ received in the threaded portion 42 of the valve into engagement with the its extreme left-hand position relative to the drawings'as extending the leg. It is only when the valve 90 is in this position that the quantity flow control valve 74 becomes an operative part of the valve device. Pressure fluid entering the drill via the feed line18 passes across the drill control valve 90 and is ported to the rotary control valve 74 via the internal passage 18A, the chamber formed by the annular groove 32 within the bore 11, the passage 52, the intermediate passage 58, across the annular groove 1% of the valve 90 within the bore 4-0, through passage 60 and the port 80 to the chamber 76. The pressure fluid in the chamber 76 is then directed to the upper chamber 14A of the feed leg 14. via the port 73, the passage 48, the chamber formed by the annular groove 36 in the bore 11, and the internal passage 103 in the drill 10. The chamber 76 always communicates with the passage 48 due to the annular groove 84 which extends around the valve 74 and intersects the ends of the port 78 and the bore 48.

As may be seen in FIGS. 6 and 7, the ports 82 and 80 have'reversely extending throttling grooves 88 and 86 respectively to control the fluid entering the chamber 76 and also to control the amount of pressure fluid therefrom which may be discharged to atmosphere through the ports 32 and 64. Rotation in one direction of the valve 74 will rotate the port 8t away from the passage ti providing progressively restricted flow through metering groove 36, thus finally cutting flow of pressure fluid to the chamber 76 and at the same time cause the port 32 to fully align with the port 64 and thus the top chamber 14A of the feed leg 14 would be fully vented. Conversely, rotation in the other direction of the valve 74 would'cause the port 86 to fully align with the passage 69 to permit maximum flow of pressure fluid into the chamber 76 and at the same time rotate the metering groove 88 out of alignment with the exhaust port 64 and thus full pressure fluid would then be delivered to the top chamber 14A of the feed leg 14. Simultaneously, the bottom chamber 148 of the feed leg is vented via the passage 10A, the annular groove 34, the passages 5t and 54, the bore and a hole 114 in the wall of the housing of control valve 90.

When the operator commences his drilling operation, he may position the valve 74 to obtain the desired force acting to extend the leg 14. As long as the operator is drilling insimilar ground structure, he would not want to change the setting of the rotary control valve 74. Should an emergency arise, such as breaking a drill steel, the operator would merely have to depress the plunger $2 to cause valve 90 to shift to the position as is shown in FIG. 4 which we may call a feed release position. Pressure fluid in the passage 52 flows into the valve bore 40 into the annular groove 106. However, the lands 164 and 103 now prevent the fluid from flowing to any other passage and thus is cut ofi from the feed leg 14. Feeding of the drill is thus discontinued.

When the operator completes his drilling operation with the valve 90 in the position shown in FIG. 3 and desires to move to another location to drill a second hole, he merelydepresses the plunger 92 to its full extent as shown in FIG. 5 which is the power retract position. As may now be seen, air inthe passage 52 now enters the bore 40 via the passage 58 in the chamber defined by the annular groove 106 and goes to the lower chamber 1413 of the feed leg 14 via the passage 54, the passage 50, the chamber definedlby the annular groove 34 in the bore 11 and the passage 10A. At the same time, the upper chamber 14A of the leg 14 is vented to atmosphere via the passage 48, the passage 62, the chamber in the bore 40 defined by the annular groove 102, and port 43. As may be more clearly seen, the pressure tions to close the inlet, delivery and connecting passages;

fluid does not enter the rotary control valve 74 when 'th valve ht) is in the power retract position.

1. A valve device comprising a housing having an' inlet passage, an exhaust passage, a delivery passage, and

a connecting passage; a valve movable in said housing from one terminal position in which said valve connects the delivery and exhaust passages and simultaneously connects the connecting and inlet passages to a second terminal position in which said valve connects the delivery and inlet passages and simultaneously closes the connecting passage; said valve movable to a position intermediate the terminal positions in which said valve closes the inlet, delivery and connecting passages; said housing having a second delivery passage and an exhaust port; and a'second valve to connect the connecting passage to the second delivery passage and the exhaust port, and being movable to vary the extent of communication of such passages and port to control the flow through the second delivery passage.

2. The valve device according to claim 1 and the secand valve being movable between terminal positions to'provide an unrestricted connection between the connecting and second delivery passages and simultaneously to close the exhaust port in one of the terminal positions, and to provide an unrestricted connection between the second delivery passage and the exhaust port and simultaneously to close the connecting passage in the other of the terminal positions. A

3. A valve device comprising a housing having an inlet passage, a pair of exhaust passages, a delivery passage, and a connecting passage; a valve movable in said' housing from one terminal position to connect the de-' livery and one of the exhaust passages and simultaneously the connecting and inlet passages to a second terminal position to connect the delivery and inlet passages and simultaneously to close the connecting passage; said valve movable to a position intermediate the terminal posisaid housing having a second delivery passage and an to close the inlet, first and second delivery, and connectexhaust port, said second delivery passage being closed by the valve in the first terminal and'intermediate posi-, tions and connected to the other exhaust passage by the valve in the second terminal position; and a second valve to connect the connecting passage to the second delivery passage and the exhaust port, and movable to vary the extent of communication of such passages and port to control the flow through the second delivery passage.

4. A valve device comprising ahousing having an inlet passage, a pair of exhaust passages, first and second delivery passages, and a connecting passage; a. valve I movable in said housing from one terminal position to connect the first delivery and one of the exhaust passages and simultaneously the connecting and inlet passagesto a second terminal position to connect the first delivery and inlet passages andsimultaneously the second de-.

livery and the other of the exhaust passages; said valve movable to a position intermediate the terminal positions ing passages; said housing having an exhaust port; and a second valve to connect theconnecting passage to the second delivery passage and the exhaust port, and being the second valve formed is movable between two terminal positions to provide unrestricted flow of the pressure fluid to the second'delivery passage in one of the terminal positions and to progressively restrict such flow References Cited in the file of this patent UNITED STATES PATENTS 1,731,718 Galloway et a1. Oct. 15, 1929 1,764,098 Galloway June 17, 1930 1,764,099 Galloway June 17, 1930 Galloway Q June 24, 1930 Galloway Jan. 6, 1931 Gifford et a1. Sept. 16, 1941 Gardiner Oct. 30, 1951 [Carr Feb. 26, 1952 Loft Dec. 16, 1952 Pearson Sept. 21, 1954 Feucht Mar. 15, 1955 Towler et a1; 1 Aug. 20, 1957 Curlett Sept. 3, 1957 Palmer Jan. 26, 1960 

1. A VALVE DEVICE COMPRISING A HOUSING HAVING AN INLET PASSAGE, AN EXHAUST PASSAGE, A DELIVERY PASSAGE, AND A CONNECTING PASSAGE; A VALVE MOVABLE IN SAID HOUSING FROM ONE TERMINAL POSITION IN WHICH SAID VALVE CONNECTS THE DELIVERY AND EXHAUST PASSAGES AND SIMULTANEOUSLY CONNECTS THE CONNECTING AND INLET PASSAGES TO A SECOND TERMINAL POSITION IN WHICH SAID VALVE CONNECTS THE DELIVERY AND INLET PASSAGES AND SIMULTANEOUSLY CLOSES THE CONNECTING PASSAGE; SAID VALVE MOVABLE TO A POSITION INTERMEDIATE THE TERMINAL POSITIONS IN WHICH SAID VALVE CLOSES THE INLET, DELIVERY AND CONNECTING PASSAGES; SAID HOUSING HAVING A SECOND DELIVERY PASSAGE AND AN EXHAUST PORT; AND A SECOND VALVE TO CONNECT THE CONNECTING PASSAGE TO THE SECOND DELIVERY PASSAGE AND THE EXHAUST PORT, AND BEING MOVABLE TO VARY THE EXTENT OF COMMUNICATION OF SUCH PASSAGES AND PORT TO CONTROL THE FLOW THROUGH THE SECOND DELIVERY PASSAGE. 